1. Field of the Invention
The present invention relates broadly to the field of safety systems for use in controlling undesired flow of well fluids from hydrocarbon producing wells. Specifically, the present invention relates to an improved simplified construction of a primary rotatable ball-type surface controlled tubing retrievable subsurface safety valve which is procluded from ball rotational overtravel. The ball may be locked open in the event of a primary valve malfunction and a backup surface controlled through the flow line installed subsurface valve operably mounted therein as a redundant safety system.
2. Description of the Prior Art
Surface controlled subsurface valves used as safety systems to control flow of well fluids from hydrocarbon producing wells are known. Some early examples of such subsurface valves and the well safety systems they have provided are disclosed in the following patents which are assigned to the assignee of the present invention:
______________________________________ Patentee U.S. Pat. No. Issue Date ______________________________________ Knox 2,518,795 August 15, 1950 Knox 3,035,808 May 22, 1962 Lewis 3,509,913 May 5, 1970 ______________________________________
Generally such safety valves were of the tubing retrievable type with the tubular valve housing made-up in and forming a portion of the well tubing and therefore retrievable with the well tubing. The quick acting ball-type closure element with its desirable full opening and straight through flow passage characteristics was disclosed in the Knox '808 patent.
A detailed discussion of the subsurface safety valve prior art is found in the following selected U.S. patents which are also assigned to the assignee of the present invention:
______________________________________ Patentee U.S. Pat. No. ______________________________________ Mott 3,901,321 Mott 3,993,136 Mott 4,019,514 Mott 4,026,362 ______________________________________
All of the seven above identified patents, as well as any other patent subsequently identified herein, are hereby fully incorporated herein as written description by this specific reference for any and all purposes as completely as if such patent was set forth verbatim herein.
In addition to the previously selected and identified patents, Applicant's assignee is also the owner of numerous additional patents and patent applications disclosing well safety systems and components therefor. Many other inventors have also been active in developing this useful technology as will be considered hereinafter. It is to be understood that other patents not mentioned herein may be as equally relevant as prior art to those that are mentioned, but that best efforts have been made to identify and consider the best prior art.
U.S. Pat. No. 2,998,077 to Keithahn is entitled "Subsurface Safety Shut-Off Valve Apparatus". The disclosed tubing retrievable surface control subsurface safety valve employs a modified ball-type flow closure element which may be locked in the open position using a wire-line tool to shift a radially expandable locking detent. No provision for installation of a back-up valve is made in the Keithahn disclosure. See also Mott Canadian Pat. No. 955,915 (originally filed as U.S. patent application Ser. No. 72,034 on Sept. 14, 1970 and as U.S. Pat. No. 4,550,780) which discloses a releasable locking means and a back-up valve capability.
U.S. Pat. No. Re. 28,131 (originally U.S. Pat. No. 3,741,249) names Kurt Leutwyler as inventor and is entitled "Ball Valve With Resilient Seal". Each chordal flat formed on the ball-type flow closure element is provided with a radial recess for receiving the eccentric rotation crank pin and a lug defining a pair of rotational movement limit stop shoulders for engaging the reciprocating ball cage member. By engaging the ball cage member with the stops, the ball is prevented from rotational overtravel in response to ball longitudinal movement greater than that required for rotation. The stops which engage or co-act with the movable cage to insure that the ball is held in the aligned full opening position rather than partially open position creating a flow throttling impingement and resulting valve damaging erosion.
Crowe U.S. Pat. No. 3,771,603 is entitled "Dual Safety Valve Method And Apparatus". The disclosed arrangement for limiting rotational travel of the two parallel flow path ball closure elements in a dual completion well is substantially identical to that of related U.S. Pat. No. 3,896,876 to be discussed hereinafter.
Crowe U.S. Pat. No. 3,850,242 entitled "Subsurface Safety Valve" is stated to be related to both U.S. Pat. Nos. 3,797,573 and 3,771,603. The mounting and rotational travel limits of the ball are provided by a pair of stop shoulders formed on each of the ball chordal flats in a manner similar to that of U.S. Pat. No. Re. 28,131. A non-releasable wire-line actuated lockout sleeve is provided in the tubing retrievable valve for permanently locking the valve open. Shifting of the lockout sleeve by wire-line operations to effect locking also communicates the control fluid pressure into the bore of the well tubing for operating the supplemental subsurface safety valve.
Crowe U.S. Pat. No. 3,868,995 entitled "Sub-Surface Safety Valve" discloses the use of a split ball flow closure element to equalize well fluid pressure before ball opening rotation begins. The ball rotational limit stop is also formed on each ball flat by a lug or projection forming the desired stop shoulders. Both a concentric ball mounting pin receiving recess and a radially extending eccentric crank pin receiving recess are formed on each ball flat.
Crowe U.S. Pat. No. 3,896,876 also discloses a ball closure mounting having an eccentric pin radial slot and rotational limit shoulders formed in each chordal flat of the ball. A lockout sleeve is provided in the tubing retrievable valve for enabling the ball-type closure element to be permanently locked in the open position. Shifting of the locking sleeve also enables communication of the control fluid pressure to the wire-line retrievable valve in a manner similar to U.S. Pat. No. 3,850,242.
U.S. Pat. No. 3,971,438 also names Crowe as inventor and is entitled "Wire-line Safety Valve With Split Ball". The disclosed valve also uses a two piece ball to equalize the fluid pressure prior to rotating the ball open. Each chordal flat of the ball closure element has a central or concentric recess for receiving a longitudinally movable pin on the reciprocating valve operator and a radial slot for receiving an eccentric ball crank pin mounted on the valve housing. Longitudinal movement of the valve operator relative to the valve body moves the ball relative to the fixed eccentric pin to crank the ball between the open and closed position. Raised lugs 114 on the ball flats engage the operator mechanism to maintain the fully aligned ball open position when the valve operator travels downwardly a longitudinal distance greater than that required to rotate the ball open.
U.S. Pat. No. 3,763,932 to Dinning is entitled "Surface Operated, Subsurface Safety Valve Assembly". The flapper-type closure tubing retrievable subsurface safety valve is adapted to be locked open by wireline operations and a wireline flapper-type retrievable valve installed therein for back-up operation. To establish communication between the control fluid operating chamber and the bore of the tubing retrievable valve to enable controlled operation of the back-up valve it was necessary to perforate the operator sleeve.
U.S. Pat. No. 3,078,923 to Tausch discloses a wireline retrievable surface control subsurface safety valve having a flapper-type flow closure and carrying the control fluid pressure responsive mechanism. The valve is disclosed as being operably received in a conventional landing nipple.
U.S. Pat. No. 3,627,042 discloses the use of a side pocket mandrel as a tubing retrievable housing for operably receiving a wireline retrievable flapper-type subsurface safety valve having control fluid pressure responsive surfaces.
Tausch U.S. Pat. No. 3,786,863 is entitled "Well Safety Valve System". A wireline actuated valve mechanism is installed in the well tubing adjacent a conventional landing nipple. The control fluid conduit is run from the surface to the valve mechanism and then to the landing nipple. Prior to retrieving the wireline retrievable safety valve in the landing nipple, the valve mechanism is closed to prevent escape of the hydraulic control fluid from the control fluid conduit when the wire-line valve is removed from the landing nipple. See also Krause U.S. Pat. No. 4,249,599.
U.S. Pat. No. 3,786,865 to Tausch is entitled "Lockout For Well Safety Valve". The disclosed tubing retrievable valve lockout sleeve is located below the flapper closure element and is shifted upwardly by a wire-line operation to hold the flapper in the open position.
U.S. Pat. No. 3,786,866 is also "Lockout For Well Safety Valve" and discloses two embodiments of a tubing retrievable valve. Telescoping portions of the operator sleeve may be extended to lock the flapper open.
Tausch U.S. Pat. No. 3,786,867 is entitled "Well Safety Valve System And Method Of Operation". The disclosed invention provides a drain valve operated by wireline for removing liquid from the control fluid conduit. The absence of liquid in the control fluid conduit avoids the effect of a hydrostatic head on the valve and thereby installation at a greater depth in the well. Pressurized gas is used as a control fluid in the conventional manner to operate the valve.
Watkins U.S. Pat. No. 3,799,204 discloses an equalizing valve actuated by a lost motion linkage of the valve operator. The initial movement of the operator opens the equalizing valve to eliminate the pressure differential across the primary flapper closure element prior to attempting to open the flapper.
U.S. Pat. No. 3,799,258 is entitled "Subsurface Well Safety Valve". The disclosed surface controlled tubing retrievable subsurface valve as well as the wireline retrievable backup valve employ flapper-type closure elements for controlling flow. The tubing retrievable valve is equipped with a shear pin retained lockout sleeve which also closes a control fluid port. When sheared, the sleeve locks the tubing retrievable valve open and communicates the control fluid to the back-up valve installed in the bore of the tubing retrievable valve.
U.S. Pat. No. 4,077,473 is entitled "Well Safety Valve" and is similar to U.S. Pat. No. 3,981,358. The flapper-type tubing retrievable valve incorporates a mechanism for resetting the tubular operator to the proper operating length after a prearranged telescopic collapse due to the well shut-in pressure differential opposing opening movement of the flapper element.
Bostock U.S. Pat. No. 2,894,715 discloses a tubing retrievable surface control subsurface safety valve in which the ball flow closure element does not move longitudinally in rotating to and from the open and closed positions. Rotation is effected by a radial lug on each ball flap received within a slot formed on the reciprocating operator.
Fredd U.S. Pat. No. Re. 25,471 (originally U.S. Pat. No. 3,007,669) discloses a number of embodiments of a ball valve in which the ball flow closure element having a flow port formed therethrough moves longitudinally during rotational operation. Each of the two parallel chordal flats formed on the rotatable ball has a cam slot extending radially across the flat. A first cam lug on the reciprocating operator and a second cam lug fixed to the tubular valve body are operably positioned in each slot. The fixed cam lugs include pivots surrounded by rotatable blocks which provide large bearing surfaces in the cam slots to better distribute the stresses created during valve operation. The operator cam lugs have rotatable rollers which engage opposite sides of the cam slots for enabling the greater sliding motion of the operator cam lugs effecting the longitudinal movement of the ball needed to provide operating rotation.
U.S. Pat. No. Re. 26,149 discloses a conventional tubing landing nipple having a separate control fluid conduit extending to the surface. A wireline retrievable valve operably positioned in the landing nipple receives control fluid pressure from the surface for controlling operation of the wireline retrievable valve. The control fluid is communicated to a pressure responsive surface provided on the valve for effecting surface controlled valve operation. Both a sleeve valve and a geared double flapper valve is disclosed for wireline installation in the landing nipple.
A ball-type wireline retrievable valve having pressure responsive means for installation in a landing nipple is disclosed in Grimmer et al. U.S. Pat. No. 3,292,706. A fluid pressure operated wireline retrievable subsurface safety valve is also disclosed in Bostock U.S. Pat. No. 3,002,566.
A surface control manifold for a subsurface safety valve is disclosed in Tamplen et al. U.S. Pat. No. 2,998,070. Typical surface controls are also disclosed in U.S. Pat. Nos. 3,419,076 and 3,675,720. See also U.S. Pat. No. 4,082,147.
U.S. Pat. No. 2,973,005 is entitled "Ball-Type Surface Safety Valve" in which the ball valve mechanism moves longitudinally in order to effect rotation of the ball member.
Taylor U.S. Pat. No. 3,642,070 discloses a wireline retrievable ball-type valve for landing in conventional landing nipples using the locating and locking mandrel described in Tamplen U.S. Pat. No. 3,208,531. The ball is supported from a pair of oppositely disposed support brackets having mounting pins which are received within concentric openings formed on each of the two ball flats. The eccentric operator pins are fixed to the housing for effecting rotation of the ball while ball alignment pins are employed to prevent rotation of the support brackets during ball rotation.
U.S. Pat. No. 3,233,860 is entitled "Ball Valve Improvement". The valve operator sleeves above and below the ball are operably connected so that only a portion of the force required for effecting rotation of the ball is transmitted through engagement with the ball member.
U.S. Pat. No. 3,310,114 is entitled "Pressure Operated Safety Valve". The disclosed valve employs a rotatable ball member having concentric mounting pins received in the concentric recess of the ball. A pair of eccentric pins rigidly secured to the valve housing engage radially extending slots formed in the ball flats for providing the cranking or rotational movement. The connector members holding the ball for rotation are held against relative circumferential rotation by a pair of fixed pins.
U.S. Pat. No. 2,908,330 discloses a valve having a ball-type closure element movable from the open to the closed position but which may not be reopened in the well. The ball element is provided with eccentric pins which move in corresponding cam tracks to effect this one time operation.
Taylor, Jr. U.S. Pat. No. 3,696,868 discloses a surface controlled tubing retrievable ball-type subsurface safety valve which may be locked open using a wireline tool to shift a locking sleeve positioned above the upper valve operator sleeve. The valve lock open may be either permanent or releasable depending upon the disclosed embodiment employed. The tubing retrievable valve is also provided with an equalizing valve arrangement such as disclosed in Dollison U.S. Pat. No. 3,583,442 to prevent opening of the ball with a potentially damaging pressure differential formed across the flow closure element. The ball closure element is concentrically mounted by a pair of longitudinally movable pins and cranked to the open position by a pair of fixed eccentric pins. A third set of pins are employed to prevent rotation of the concentric mounting fingers of the operator assembly. A second hydraulic control fluid conduit is disclosed for balancing or offsetting the hydrostatic head of the hydraulic control fluid in the conventional operating control fluid conduit if desired. A supplemental or wireline retrievable valve may be installed in the locked open tubing retrievable valve and operated by the hydraulic fluid control of the tubing retrievable valve to provide a back-up safety system. Fluid communication between the hydraulic control fluid conduit and the pressure responsive operating mechanism of the valve is established by either perforating the upper operator of the locked open valve or by providing a port associated with the locking sleeve if desired. Details of the ball mounted linkage are stated to be disclosed in U.S. Pat. No. 3,583,442 to Dollison. The packoff tool or mounting housing for the supplemental subsurface safety valve are said to be disclosed in Tamplen U.S. Pat. No. 3,208,531. If a supplemental valve is used it is such that is disclosed in Dollison U.S. Pat. No. 3,583,442.
Taylor U.S. Pat. No. 3,826,462 is entitled "Large Bore Rotary Safety Valves For Wells". The disclosed valve is of a wireline type carrying the control fluid pressure responsive mechanism and having windows formed in the housing to provide clearance for operating rotation of the large diameter ball element. See also Mott U.S. Pat. No. 4,067,387.
U.S. Pat. No. 3,860,066 discloses a tubing retrievable safety valve having alternate flow closure elements. A poppet-type closure element, a flapper type closure element and a ball type closure element are disclosed as functionally interchangeable flow control elements. The operating or actuating mechanism for the disclosed valves are provided with remote or surface controls as well as with direct well condition responsive means.
Gazda U.S. Pat. Nos. 3,874,634 and 3,990,511 disclose a tubing retrievable surface controlled subsurface safety valve having a sliding sleeve internal valve which controls communication between the interior of the tubing retrievable valve and the control fluid pressure communicated from the surface through the a separate control line. The sliding sleeve valve is opened and closed automatically as the wire-line or through the flow line movable safety valve is installed in or removed from the safety valve.
U.S. Pat. No. 3,882,935 to Calhoun is entitled "Subsurface Safety Valve With Auxiliary Control Fluid Passage Operable In Response To An Increase In Control Fluid Pressure". The primary tubing retrievable surface controlled subsurface safety valve may be locked open in a manner similar to Taylor U.S. Pat. No. 3,696,868. Shearable seal plugs are employed to normally seal the control fluid pressure system from the flow passage of the tubing retrievable valve. By pressuring the control fluid pressure above the normal operating range, the plugs shear out to establish a control fluid path to the flow passage and the supplemental valve operably positioned therein. In one alternate embodiment, a rupture disk, actuated by shifting of the locking sleeve, is employed to establish to communication of the control fluid. Another embodiment equalizes control fluid pressure across the shear plug or ruptured disk until the lock sleeve is shifted to preclude an inadvertent, premature activation of the control fluid passage to the supplemental valve. In a fourth embodiment, a port formed in the locking sleeve is shifted into communication with a control fluid port to form the flow passage.
The disclosed safety valve of U.S. Pat. No. 4,193,450 is entitled "Surface Controlled Subsurface Safety Valve" and is of the through-the-flow line (TFL) type carrying the control pressure responsive means and adapted to be operably secured in a dual line landing nipple. The various operating fluid pressure zones are arranged to provide for valve closure (fail-safe operation) in the event of a seal failure. The disclosed landing nipple is stated to be the subject matter of a patent application, Ser. No. 960,169.